Mannan-binding lectin in human serum, cerebrospinal fluid and brain tissue and its role in Alzheimer's disease

Mannan-Binding lectin (MBL) is a serum lectin which can activate the classical complement pathway. Complement proteins of the classical pathway have been found in the brains of patients with Alzheimer's disease (AD) in association with AD brain pathology. To investigate the role for MBL in AD we have looked for its presence in the brain by immunohistochemistry and determined the levels of MBL in paired samples of cerebrospinal fluid and serum from AD patients and controls. MBL was detected in association with blood vessels in the brain tissue of both AD patients and control subjects. There was no apparent difference in the distribution of MBL in the brain tissue between the two groups. The mean concentration of MBL in the CSF was 44% lower in AD patients than in controls (AD 154 +/- 35 pg/ml, n = 19; non-AD 276 +/- 50 pg/ml, n = 15, p < 0.05). The levels of MBL in serum were not significantly different in the two groups. Thus, this study shows that MBL is associated with blood vessels in the brains of both AD and control subjects. Moreover, CSF levels of MBL appear to be lower in AD patients than in control subjects which may indicate a higher degree of MBL consumption connected with complement activation in the AD patients.     

Self-regulating childhood asthma: a developmental model of family change

This article tests a model of self-regulatory development in which families' cognitive beliefs and behavioral skills for managing asthma symptoms emerge in four successive phases: asthma symptom avoidance, asthma acceptance, asthma compliance, and asthma self-regulation. Confirmatory factor analyses revealed that the hypothesized multiphase model provided the best factorial fit for phase items. Subsequent Guttman analyses of the families' phase scores revealed a high degree of sequential ordering. Finally, trend analyses of family phase differences revealed a significant negative linear relation with measures of asthma severity and a significant positive linear relation with physician care and concern measures, asthma regulatory measures, and beliefs in Western biomedical practices. Despite receiving primary care for asthma at a major metropolitan university hospital, 83% of the sample were classified as precompliant. The phase model of asthma self-regulatory development offers a qualitative approach for investigating the psychological determinants of asthma self-regulatory behavior.     

Twice-daily compared with once-daily thoracic radiotherapy in limited small-cell lung cancer treated concurrently with cisplatin and etoposide

BACKGROUND: For small-cell lung cancer confined to one hemithorax (limited small-cell lung cancer), thoracic radiotherapy improves survival, but the best ways of integrating chemotherapy and thoracic radiotherapy remain unsettled. Twice-daily accelerated thoracic radiotherapy has potential advantages over once-daily radiotherapy. METHODS: We studied 417 patients with limited small-cell lung cancer. All the patients received four 21-day cycles of cisplatin plus etoposide. We randomly assigned these patients to receive a total of 45 Gy of concurrent thoracic radiotherapy, given either twice daily over a three-week period or once daily over a period of five weeks. RESULTS: Twice-daily treatment beginning with the first cycle of chemotherapy significantly improved survival as compared with concurrent once-daily radiotherapy (P=0.04 by the log-rank test). After a median follow-up of almost 8 years, the median survival was 19 months for the once-daily group and 23 months for the twice-daily group. The survival rates for patients receiving once-daily radiotherapy were 41 percent at two years and 16 percent at five years. For patients receiving twice-daily radiotherapy, the survival rates were 47 percent at two years and 26 percent at five years. Grade 3 esophagitis was significantly more frequent with twice-daily thoracic radiotherapy, occurring in 27 percent of patients, as compared with 11 percent in the once-daily group (P<0.001). CONCLUSIONS: Four cycles of cisplatin plus etoposide and a course of radiotherapy (45 Gy, given either once or twice daily) beginning with cycle 1 of the chemotherapy resulted in overall two- and five-year survival rates of 44 percent and 23 percent, a considerable improvement in survival rates over previous results in patients with limited small-cell lung cancer.     

Chylothorax or leakage of total parenteral nutrition?

The diagnosis chylothorax is based on a chemical analysis of the pleural effusion. According to the literature, this analysis can be rather straightforward, comprising measurements of triglycerides, chylomicrons, and cholesterol. In this report we present an autopsy case that alerted us to interpret these results critically. Although the laboratory tests of the pleural effusion in this patient with parenteral nutrition suggested chylothorax, additional tests (potassium (11.3 mmol.L(-1)) and glucose (128 mmol.L(-1)) proved otherwise. Comparison of the pleural effusion analysis and the content of the parenteral nutrition led to the final conclusion that the effusion was due to a leakage of parenteral nutrition instead of chylothorax. We therefore suggest adding glucose and potassium measurements to the biochemical work-up of a patient under suspicion of chylothorax.     

Polyethyleneglycol-stabilized manganese-substituted hydroxylapatite as a potential contrast agent for magnetic resonance imaging: particle stability in biologic fluids

RATIONALE AND OBJECTIVES: Polymer-stabilized manganese(II)-substituted hydroxylapatite (MnHA) has been investigated as a particulate contrast agent for magnetic resonance imaging. The MnHA core requires a polymer coating to retard opsonization, thereby prolonging its systemic persistence. Therefore, the aim of this study was to assess the stability of various formulations in biologic media in vitro. METHODS: Polyethyleneglycol-coated manganese(II)-substituted hydroxylapatite particles were studied in bovine plasma as a function of the concentration of polymer in the formulation. Particle sizing techniques and nuclear magnetic resonance proton relaxometry were used to evaluate both in vitro and in vivo stability. RESULTS: A small-sized particle (approximately 10 nm diameter) that is stable in bovine plasma and rabbit whole blood was formed in formulations with high amounts of polymer concentration. In formulations with low amounts of polymer concentration, larger-sized particles (approximately 100 nm diameter) were present along with the small-sized population. The larger particles de-aggregated into the small-size particle distribution on dispersion in bovine plasma and rabbit whole blood. CONCLUSIONS: Ultrasmall particles with high surface coat were stable in plasma, whereas larger aggregates de-aggregated. Unlike Mn2+, the interaction of polyethyleneglycol-stabilized manganese(II)-substituted hydroxylapatite with plasma proteins was weak.     

Hantavirus pulmonary syndrome treated with inhaled nitric oxide

BACKGROUND: A retrospective study was done to assess the correlation between endometrial cells on routine cervical cytology and carcinoma of the endometrium. METHODS: In a 4-year period, endometrial cells of some type were identified on the Papanicolaou (Pap) smears of 61 women, of whom 52 had further diagnostic evaluation of the endometrium. Data were analyzed with a multivariate stepwise logistic regression. RESULTS: The results indicated an association of endometrial cells in Pap smears with carcinoma of the endometrium in seven patients (13.5%). In 45 patients (86.5%), the final diagnosis was benign. Factors that impacted the diagnosis of carcinoma were the findings of atypical or cancerous endometrial cells on Pap smear and abnormal vaginal bleeding. CONCLUSIONS: These data indicate the importance of further diagnostic evaluation with endometrial sampling in postmenopausal patients with endometrial cells seen in Pap smears, especially those with abnormal bleeding.     

Role of a dynamic loop in cation activation and allosteric regulation of recombinant porcine fructose-1,6-bisphosphatase

A disordered loop (loop 52-72, residues 52-72) in crystal structures of fructose-1,6-bisphosphatase (FBPase) has been implicated in regulatory and catalytic phenomena by studies in directed mutation. A crystal structure of FBPase in a complex with three zinc cations and the products fructose 6-phosphate (F6P) and phosphate (Pi) reveals loop 52-72 for the first time in a well-defined conformation with strong electron density. Loop 52-57 interacts primarily with the active site of its own subunit. Asp68 of the loop hydrogen bonds with Arg276 and a zinc cation located at the putative potassium activation site. Leu56 and Tyr57 of the loop pack against hydrophobic residues from two separate subunits of FBPase. A mechanism of allosteric regulation of catalysis is presented, in which AMP, by binding to its allosteric pocket, displaces loop 52-72 from the active site. Furthermore, the current structure suggests that both the alpha- and beta-anomers of F6P can be substrates in the reverse reaction catalyzed by FBPase. Mechanisms of catalysis are proposed for the reverse reaction in which Asp121 serves as a catalytic base for the alpha-anomer and Glu280 serves as a catalytic base for the beta-anomer.     

Prediction of transgene integration by noninvasive bioluminescent screening of microinjected bovine embryos

Transgenesis in domestic species, as a research tool and in biotechnological applications, has been limited by the expense of producing transgenic offspring by standard microinjection techniques. A major factor is the inefficiency of maintaining large numbers of recipient females, when a high percentage of these carry nontransgenic fetuses. There are two approaches to reduce this cost, the fusion of transfected fetal fibroblasts with enucleated oocytes, and the screening of microinjected embryos for transgene integration in blastocysts, prior to transfer. Here, we develop a luminescent screening system to select transgenic bovine embryos. A transgene with scaffold attachment regions flanking the murine HSP70.1 promoter linked to firefly luciferase cDNA, was microinjected into pronuclei of in vitro produced zygotes. At the blastocyst stage, the transgene was induced by heat shock (45 degrees C, 15 min) and 4-6 h later, luciferase expression was analyzed by photon counting imaging. Screened blastocysts were transferred to recipients and day 50 fetuses or calves were analyzed by PCR and Southern blot for transgene integration. When nonluminescent blastocysts were transferred, transgene integration was never observed. Of 13 fetuses derived from luminescent blastocysts, 3 contained integrated transgenes that were functional in all tissues examined. Image analysis of the signal emitted by positive blastocysts revealed that 9 nontransgenic fetuses were obtained from blastocysts that exhibited a localized luminescent signal. On the other hand, 3 of 4 fetuses derived from blastocysts that emitted light over more than 70% of their surface were transgenic. Thus, by selecting luminescent blastocysts on the basis of both signal intensity and distribution, the number of recipient females required to produce transgenic offspring can be greatly reduced. Using this technique it should also be possible to improve the efficiency of transgenesis by microinjection through studies in which vector design and integration conditions are examined at the blastocyst stage.